The invention pertains to an intermediate film storage device for a section of photographic material of limited length (section of film) with feed rolls, exit rolls, intermediate rolls which separate a first buffer from a second buffer, and a guiding device which guides the section of film from the feed rolls to the intermediate rolls.
Films, papers or other light-sensitive coated carriers can be used as photographic materials. A section of photographic material of limited length will be designated in what follows as "section of film". In the automatic processes common today, a section of film must pass through different stations which, under certain circumstances, may each run at different speeds. For example, the section of film passes an exposure station in which it is exposed to light at predetermined points to produce an image and a development station in which the image exposed in the exposure station is developed and fixed. If a photo-composition instrument or scanner is used at the exposure station, the speed of the section of film varies as it passes through this instrument. However, the section of film must also pass through a roll development machine which in many cases, is used as a development station through which the film section passes at a constant speed so that the chemical processes necessary for developing and fixing can occur at pre-determined times.
In order to equalize the operating speeds of the various stations, it is known to use intermediate film storage devices. In the intermediate film storage device, the section of film is typically laid into a loop which forms a certain reserve of film with the aid of which the different speeds at neighboring stations can be equalized. In a known intermediate film storage device (European Patent EP 183,982 B1), the intermediate film storage device contains two buffers which are separated by an arrangement of intermediate rolls. This known intermediate film storage device, however, is intended for a continuous film, i.e., not for sections of film. For example, after a separation of the film due to certain operating conditions, both of the buffers are needed to be able to re-introduce the new head of the film again into the intermediate film storage device as quickly as possible, without having to wait for the intermediate film storage device to become completely empty. To do so, the separated end of the film is rewound from the first buffer to the second buffer. The first buffer, which will then be empty, can then be provided with the head of the film and the succeeding fresh film. However, the known intermediate film storage device is not suitable for processing sections of film.
It is the object of the present invention to provide an intermediate film storage device which is suitable for the intermediate film storage of sections of film without negatively influencing the operation of adjacent stations.